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authorDavid S. Miller <davem@davemloft.net>2018-01-16 22:42:14 -0500
committerDavid S. Miller <davem@davemloft.net>2018-01-16 22:42:14 -0500
commit7018d1b3f20fb4308ed9bc577160cb8ffb79b62a (patch)
treeb61a17c694d3cdc3490b190c35104b936bcc6638 /Documentation
parentbnxt_en: don't update cpr->rx_bytes with uninitialized length len (diff)
parentMerge branch 'bpf-libbpf-cleanups' (diff)
downloadlinux-dev-7018d1b3f20fb4308ed9bc577160cb8ffb79b62a.tar.xz
linux-dev-7018d1b3f20fb4308ed9bc577160cb8ffb79b62a.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-01-17 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add initial BPF map offloading for nfp driver. Currently only programs were supported so far w/o being able to access maps. Offloaded programs are right now only allowed to perform map lookups, and control path is responsible for populating the maps. BPF core infrastructure along with nfp implementation is provided, from Jakub. 2) Various follow-ups to Josef's BPF error injections. More specifically that includes: properly check whether the error injectable event is on function entry or not, remove the percpu bpf_kprobe_override and rather compare instruction pointer with original one, separate error-injection from kprobes since it's not limited to it, add injectable error types in order to specify what is the expected type of failure, and last but not least also support the kernel's fault injection framework, all from Masami. 3) Various misc improvements and cleanups to the libbpf Makefile. That is, fix permissions when installing BPF header files, remove unused variables and functions, and also install the libbpf.h header, from Jesper. 4) When offloading to nfp JIT and the BPF insn is unsupported in the JIT, then reject right at verification time. Also fix libbpf with regards to ELF section name matching by properly treating the program type as prefix. Both from Quentin. 5) Add -DPACKAGE to bpftool when including bfd.h for the disassembler. This is needed, for example, when building libfd from source as bpftool doesn't supply a config.h for bfd.h. Fix from Jiong. 6) xdp_convert_ctx_access() is simplified since it doesn't need to set target size during verification, from Jesper. 7) Let bpftool properly recognize BPF_PROG_TYPE_CGROUP_DEVICE program types, from Roman. 8) Various functions in BPF cpumap were not declared static, from Wei. 9) Fix a double semicolon in BPF samples, from Luis. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/fault-injection/fault-injection.txt68
1 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 918972babcd8..f4a32463ca48 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -30,6 +30,12 @@ o fail_mmc_request
injects MMC data errors on devices permitted by setting
debugfs entries under /sys/kernel/debug/mmc0/fail_mmc_request
+o fail_function
+
+ injects error return on specific functions, which are marked by
+ ALLOW_ERROR_INJECTION() macro, by setting debugfs entries
+ under /sys/kernel/debug/fail_function. No boot option supported.
+
Configure fault-injection capabilities behavior
-----------------------------------------------
@@ -123,6 +129,29 @@ configuration of fault-injection capabilities.
default is 'N', setting it to 'Y' will disable failure injections
when dealing with private (address space) futexes.
+- /sys/kernel/debug/fail_function/inject:
+
+ Format: { 'function-name' | '!function-name' | '' }
+ specifies the target function of error injection by name.
+ If the function name leads '!' prefix, given function is
+ removed from injection list. If nothing specified ('')
+ injection list is cleared.
+
+- /sys/kernel/debug/fail_function/injectable:
+
+ (read only) shows error injectable functions and what type of
+ error values can be specified. The error type will be one of
+ below;
+ - NULL: retval must be 0.
+ - ERRNO: retval must be -1 to -MAX_ERRNO (-4096).
+ - ERR_NULL: retval must be 0 or -1 to -MAX_ERRNO (-4096).
+
+- /sys/kernel/debug/fail_function/<functiuon-name>/retval:
+
+ specifies the "error" return value to inject to the given
+ function for given function. This will be created when
+ user specifies new injection entry.
+
o Boot option
In order to inject faults while debugfs is not available (early boot time),
@@ -268,6 +297,45 @@ trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
echo "Injecting errors into the module $module... (interrupt to stop)"
sleep 1000000
+------------------------------------------------------------------------------
+
+o Inject open_ctree error while btrfs mount
+
+#!/bin/bash
+
+rm -f testfile.img
+dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
+DEVICE=$(losetup --show -f testfile.img)
+mkfs.btrfs -f $DEVICE
+mkdir -p tmpmnt
+
+FAILTYPE=fail_function
+FAILFUNC=open_ctree
+echo $FAILFUNC > /sys/kernel/debug/$FAILTYPE/inject
+echo -12 > /sys/kernel/debug/$FAILTYPE/$FAILFUNC/retval
+echo N > /sys/kernel/debug/$FAILTYPE/task-filter
+echo 100 > /sys/kernel/debug/$FAILTYPE/probability
+echo 0 > /sys/kernel/debug/$FAILTYPE/interval
+echo -1 > /sys/kernel/debug/$FAILTYPE/times
+echo 0 > /sys/kernel/debug/$FAILTYPE/space
+echo 1 > /sys/kernel/debug/$FAILTYPE/verbose
+
+mount -t btrfs $DEVICE tmpmnt
+if [ $? -ne 0 ]
+then
+ echo "SUCCESS!"
+else
+ echo "FAILED!"
+ umount tmpmnt
+fi
+
+echo > /sys/kernel/debug/$FAILTYPE/inject
+
+rmdir tmpmnt
+losetup -d $DEVICE
+rm testfile.img
+
+
Tool to run command with failslab or fail_page_alloc
----------------------------------------------------
In order to make it easier to accomplish the tasks mentioned above, we can use